If you don't have background, don't worry because you will learn here how to design a background by this example.
New File: Take a new file.
Choose color: First set the foreground and background color.
Clouds: Go to Filter menu > Render >Apply Clouds.
Noise: Go to Filter menu > Noise >Apply Add noise.
Motion Blur: Go to Filter menu > Blur >Apply Motion Blur.
Lens correction: Go to Filter menu > Distort >Apply Lens correction.
Fill color: Fill "e77fee" color by the paint bucket tool (G key) in the new layer.
Layer setting: Now make layer settings "Normal" to "Saturation".
This is your final result
Recommend the tutorial